EP1060457B1 - Electronic device with disposable chip and method for making same - Google Patents

Abstract

An electronic chip device includes an interface support film having a support film and at least one flat conductive interface placed on the support film, as well as a microcircuit connected to the interface. The interface support film possesses such properties that it can be creased or folded on itself without deterioration. The support film possesses a thickness of less than 75 mum, the best results being obtained with a thickness of between 10 mum and 30 mum. Preferably the support film is selected from among polypropylene (PP), polyethylene (PE), polyethylene teraphtalate (PET). In one embodiment, the device includes a compensation film placed on the support film. The compensation film has a recess containing the microcircuit and its connections. The recess can contain a material to encapsulate the microcircuit and its connections.

Description

The present invention relates to the field of devices electronic chips with a communication interface and their manufacturing process. It relates in particular to smart devices including interface is contact and / or antenna such as smart card, micromodule label. It particularly targets use antenna devices punctual or disposable able to communicate at distances greater than 50 cm especially under frequencies from a few mega-Hertz to several Giga-Hertz.

We know the international application WO 97/26621 which describes a chip and antenna module can be used as a label if necessary. of the cards are obtained by inserting the antenna module into a cavity of a card body and some labels are obtained by packaging of the antenna module in any support such as a token for example.

These modules include an interface support film, called commonly printed circuit, on which are arranged at least one interface in the form of an antenna and / or in the form of connection pads, a microcircuit such as a chip connected to said interface and a material coating protecting the microcircuit and its connections. The antenna is produced on one side of the micromodule, in particular on the back thereof, while that the other side may possibly be provided with connection pads.

The interface support film must have mechanical properties due in particular to the requirements of the manufacturing processes current. In particular, it has such flexibility that it can be rolled up on coils, but also a stiffness or hardness as we can consider his training by pins meshing on lateral perforations. The stiffness of the interface support film is also such that it is brittle in case folding.

EP-A-0595549 and US-A-5528222 both describe an electronic chip device comprising a thin support film and flexible, a flat conductive interface and a microcircuit arranged on said support film.

The support films currently used are chosen from glass epoxy, polyimide, polyethylene terephthalate (PET). They have properties and following typical characteristics: a thickness of between 75 µm and 125 µm, an elongation at break of less than 75%, a resistance in temperature up to at least 160 ° C.

The interface is generally made of copper; she presents a hard surface, the tracks are generally fine (50 to 200 µm and have a precise definition of the order of a few microns. The interface generally undergoes a surface treatment for example of the Ni-Au type which still makes it harder, more suitable for welding, and protects it from oxidation.

The devices obtained according to the above request have the disadvantage to be too expensive for the use envisaged in the invention. In addition, they have limited applications that do not meet the objectives of the invention listed below.

The state of the art closest to the invention is EP-A-0 952 542 which is not state of the art that under Article 54 (3) EPC, i.e. enforceable to the invention than to the novelty. This document describes inter alia a compensation layer.

The main objective of the invention is to design a device electronic chip with or without contact, active or passive, very economical and nevertheless very reliable compatible with a production process with as few steps as possible and using as much as possible economic standard techniques, so as to promote its use and make it disposable if necessary.

Another objective is to design a device above which further is able to communicate preferably beyond 50 cm (passive device) and beyond the meter (active device).

Another objective is to design and economically realize a antenna and / or contact module which is easily and directly printable especially at the user's.

Another objective is to design a device above which is reliably usable under many conditions and on multiple supports.

Another objective is to design and economically realize smart cards or tickets with or without contact.

Some objectives are achieved by using an interface support film having completely separate properties and against the tide of those required for support films with interface in the field of smart cards presented above, but also by adopting a manufacturing process in rollers, then by adapting this process in particular at the level of the chip connection to take into account the new properties of the movie. Other objectives are achieved by a specific configuration of the device described below.

Thus, the subject of the invention is an electronic chip device according to claim 1.

According to a preferred characteristic, the electronic chip device is distinguishes in that the interface support film has properties such as that it is able to be crumpled or folded on itself without deterioration.

Good results have been obtained with a support film and a interface able to be crumpled or folded together according to a radius of curvature less than 2.5 mm and preferably less than 1 mm.

This definition corresponds to the choice of a support film whose properties are inherently degraded compared to carrier films state of the art and / or reduced thickness combined with an interface whose intrinsic properties are also degraded compared to interfaces state of the art and / or reduced thickness. The properties of each (support film and / or interface (s)) should be considered in combination. In particular, they can be greatly degraded for both, or those of one very degraded and those of the other less; the thickness of each can also be more or less reduced depending on the degree of degradation of the support film and interface materials.

Thanks to such an association and combination, we have a low-cost and reliable device despite handling that can be done undergo.

It is specified that in certain cases, the degradation, for example at level of rigidity, may be accompanied by other qualities for the product final, for example in terms of elasticity, but which cause manufacturing difficulties. Degradation must be understood compared to the properties currently sought in the smart card domain.

According to one characteristic, the support film has a thickness less than 75 µm, the best results being obtained with a thickness between 10 µm and 30 µm.

With such a thinness of the support film, the invention provides not only a saving of material with a potential impact on the price and especially a gain in the smoothness of the final device thus offering new application possibilities described below.

According to other preferred characteristics of the invention, the support film can be preferably of polymeric material having an elongation at break greater than 80%, and / or shore hardness less than 80, and / or a glass transition temperature Tg below 0 ° C, and / or a temperature melting below 130 ° C.

Preferably, the support film is chosen from polypropylene (PP), Polyethylene (PE), polyethylene terephthalate (PET). In other cases, it may include a fibrous material, for example cellulosic or textile.

The interface metal is preferably raw without treatment of surface intended to harden it, for example of the Ni-Au type. He has preferably a thickness less than 50 µm. Aluminum and its alloys are the preferred materials.

Materials like PE, PP ... are advantageously very economical because produced on rolls of great length and width in a separate area of the smart card, that of packaging. The PE / aluminum or PP / aluminum complexes that the invention proposes to use preferably as a basis for the development of an interface support film, are also widely used, particularly in the area of food packaging for yoghurt lids, champagne corks ...)

According to another characteristic, the device comprises the microcircuit preferably arranged outside the turns, in particular at an angle of the support film. More preferably, the microcircuit is placed directly on the backing film.

The device also preferably includes an element interface called "strap" on the other side to bring at least one end antenna (6) in the vicinity of the chip.

Thus, we can free up the largest possible printing surface and have a very thin device for the applications described below, the chip being in contact with the support film Using the 'strap' is an interesting solution explained in detail below.

According to the invention, the device is distinguished in that it comprises a compensation film disposed on a support film, said film compensation comprising a recess containing said microcircuit, its connections.

The recess may contain a material for coating the microcircuit and of his connections. The coating material is preferably enclosed in the less in part by the walls of the recess.

The compensation film can be used in conjunction with any other existing backing film of the prior art but there is more interest in using it in relationship with an interface support film capable of being folded in accordance with the invention.

The compensation film has, in addition to the advantages in manufacture of the device exposed subsequently, that of compensating for the height of the microcircuit and to protect it in particular to allow a printing on the entire surface of the device without damaging the microcircuit.

Its function is to flatten the surface of the device so as to have a device without protuberance and to receive if necessary a another decoration film and / or an adhesive over the microcircuit.

It also protects the microcircuit from pressure exerted on it during of its attachment to any support by an adhesive arranged in particular on the compensation film.

It also compensates for the poor mechanical strength of the film interface support in particular in its various uses.

It can be chosen from the most varied materials adapted to any use, without changing the process presented infra.

The present invention also relates to tickets and cards with the device. Preferably, they include a body of card or ticket constituted by said compensation film. That means they have a recess in which the microcircuit, the film is disposed support and interface extending out of the recess on the surface of the film compensation.

We thus obtain smart cards and economic tickets with a protection of the microcircuit if necessary.

According to an alternative embodiment, the recess is a cavity not through or closed with an additional film.

The present invention also relates to a method according to claim 24.

The interface is preferably carried out according to the economic technique engraving of printed or lithographed patterns on one or more surfaces conductive, previously secured to the support film.

Thanks to the choice of such support and interface film but also to the choice of interface production technique, we have a film low cost interface support thus helping to lower the overall price of the device.

The process also stands out in that it includes a step by which a film of compensation on said interface support film, said compensation film having at least one recess corresponding to a location of microcircuit.

This step can be used in conjunction with any other support film existing from the prior art but it is particularly interesting to use it in relation to an interface support film capable of being folded in accordance with the invention.

The compensation film reinforces the interface support film which thus may be more resistant mechanically during the process steps in particular during its displacement by traction.

It also allows the support film to be wound flat between each step if necessary, or for delivery to the customer. He thus avoids the loss-making use of a tab film commonly used as protector between the different manufacturing steps below.

The printing step can be performed on both sides of the device without damage to the microcircuit.

If the microcircuit and its connections are coated, the recess of the compensation film can have a formwork function.

The compensation film can be used if necessary to receive lateral perforations for training and positioning pin and allow packaging in reels use of means of current training.

The compensation film makes it possible to match the device with various materials. It can in particular be based on cellulose or in any material polymer, fabrics or any other material in the form of leaf.

According to another characteristic, the connection of the microcircuit by ultrasonic welding of conductive wires. More specifically, aluminum wire welding is used for studs or interfaces in aluminium.

The use of this connection technique is particularly advantageous because reliable, current and economical. As explained below, this way of proceeding posed difficulties which contraindicated it for use on an interface support film having conforming properties to the invention.

According to another characteristic, an interface support film is used provided with interface elements on both sides. In particular, we can make a capacitor frame on each side and / or 'straps' in same time as the interface.

So we can lower the cost of making these elements interface since they can be done at the same time with the same previously indicated technology. A less economical alternative would have consisted in carrying out a connection by bridge over the turns by a specific operation or the addition of a discrete capacitor.

According to another characteristic, the interface elements of each side of the backing film can be connected through the backing film by mechanical tears and mechanical contacts. If necessary, we can fix these connections by ultrasound.

The choice of the fineness of the interface support film and the choice of materials according to the invention makes it possible to use such a process of connection. It is particularly advantageous and economical because carried out without adding material and can be done in one step which can be hidden in the device manufacturing process.

• la figure 1 représente une étiquette simplifiée présentant certaines des caractéristiques de l'invention identifiable à distance par signaux radiofréquence;
• la figure 2 représente une vue en coupe de l'étiquette de la figure 1 au niveau du micromodule;
• la figure 3 représente une variante de la figure 2;
• la figure 4 représente une variante de la figure 1;
• la figure 5 représente le verso de l'étiquette de la figure 4;
• la figure 6 représente une vue de la face supérieure d'une étiquette à plages de connexion;
• la figure 7, représente une structure de carte présentant certaines des caractérisqtiques de l'invention.
• la figure 8 représente une structure de carte selon l'invention vue en coupe;
• la figure 9 représente une autre structure du dispositif de l'invention conforme à l'invention.
• la figure 10 représente une vue d'ensemble de l'exécution du procédé de l'invention;
• la figure 11 représente une vue d'ensemble d'une variante d'exécution du procédé de l'invention pour la fabrication de cartes à puce et à antenne.
• la figure 11A représente une structure de carte obtenue selon le procédé illustré à la figure précédente;
• la figure 12 représente un test de pliage.

Other characteristics and advantages of the invention will appear on reading the description below made with reference to the appended drawings, given solely by way of example in which:

• FIG. 1 represents a simplified label presenting some of the characteristics of the invention identifiable remotely by radio frequency signals;
• 2 shows a sectional view of the label of Figure 1 at the micromodule;
• Figure 3 shows a variant of Figure 2;
• Figure 4 shows a variant of Figure 1;
• Figure 5 shows the back of the label of Figure 4;
• FIG. 6 represents a view of the upper face of a tag with connection pads;
• Figure 7 shows a map structure showing some of the features of the invention.
• FIG. 8 represents a card structure according to the invention seen in section;
• Figure 9 shows another structure of the device of the invention according to the invention.
• FIG. 10 represents an overall view of the execution of the method of the invention;
• FIG. 11 represents an overall view of an alternative embodiment of the method of the invention for the manufacture of chip and antenna cards.
• FIG. 11A represents a card structure obtained according to the method illustrated in the preceding figure;
• FIG. 12 represents a folding test.

In FIG. 1, a simplified embodiment of a device electronic chip having certain characteristics of the invention is in the form of a electronic tag with chip and antenna (self and capacitor). he comprises a support film 1, a planar conductive interface formed in this example by turns 2 of a plane antenna 3 arranged in a spiral on said backing film from the edge this last inward, and a microcircuit 4 such as an integrated circuit chip connected to said interface. The antenna has two ends respectively internal and external completed or forming each of the contact pads 5, 6. The connection is in this example produced by connecting wires 7, 8.

The device also includes an adaptation capacitor produced in this example by conductive surfaces 9, 10 arranged in look on each side of the support film. If necessary, the capacitor can have traces of adjustment such as perforations or other elimination of a portion of surface which can be carried out in particular by laser. In other cases, a discrete capacitor can be added to the film or be integrated into the microcircuit.

Circuit elements 11, 12 (straps) are also used arranged on the back of the support film (Figure 5) to bring the contact 6 closer one end of the antenna or the capacitor armature, located inside the turns, at the other end 5 located outside the turns or vice versa. In fact, the 'strap' 11 allows to bring back at least one end of the antenna near the location of the chip located in this case at the outside of the antenna at the edge of the label. In the case of a film by compensation described below, the position of the chip matters less. She can be in particular inside the turns.

According to a characteristic of the invention, a coating material 13 covers at least the microcircuit and / or the connection wires so as to protect at least mechanically. In the example, (figures 1, 2) the material covers only a microcircuit location zone (zp), connections included, leaving the rest of the device stripped.

In this example, the microcircuit area occupies a surface equivalent to approximately 4mm x 5mm, while the label has a surface 40 mm x 40 mm total.

Preferably, the interface support film has properties such as to be wrinkled or folded on itself without deterioration.

FIG. 12 illustrates a folding test intended to characterize a preferred embodiment of the invention. According to this test, the interface support film must be able to fold outside of the chip area for example in two or four, the opposite edges 14, 15 are touching flat to form a fold with a small radius of curvature R. In other cases, it should be possible to crumple or crumple it with random folds having at least the above radius.

By deterioration, we mean of course a break or rupture of the film support making it unsuitable for supporting turns. We still hear a significant loss of the capacity to deform then such a deformation plastic which leads to rupture after renewal of a few folds. The interface is deteriorated when it loses its properties of electrical conduction, in particular by reduction in section, or rupture or by significant loss of elasticity which leads to rupture after a few folds (for example a dozen).

Preferred products are obtained when they support single folds radius of curvature R less than 1 mm and in particular 0.2 mm.

To achieve these performances, we use a support film in one material having an elongation at break greater than 80%, and / or Shore hardness less than 80, and / or a Tg less than zero degrees Celsius, and / or a melting temperature below 130 ° C, associated with a thickness less than 75 µm.

The best results are obtained with a film thickness support between 10 µm and 30 µm.

The support films in the example are advantageously films with very degraded properties (downgraded, less efficient) such as PP, PE, or even less degraded like PET), compared to those commonly used in card and antenna modules, such as epoxy glass or polyimides.

According to a preferred embodiment of the invention, the interface must also have appropriate dimensions and / or mechanical properties including ductility / elasticity / hardness compatible with those of the support film for pass the bend test.

In the example, the interface is made of aluminum without surface in particular in nickel / gold etc. Its thickness is less than or equal to 50 µm and preferably between 7 and 30 µm.

Where appropriate, according to an alternative, the support film can comprise a fibrous material, in particular cellulosic or textile. he can for example be simply very thin paper as above. Textile fibrous materials have the property of wrinkling without break and wrinkle reversibly.

In FIG. 3, a thickness of layer of material of protection 13 as thin as possible which covers the entire surface of the label. The thickness obtained from the area of the chip (zp) can be less than 400 µm and in particular less than 300 µm for a chip having a thickness of around 150 µm. The thickness obtained from the area outside the chip (zhp) is less than 150 µm, and in particular less than 100 µm.

In the case of FIG. 3, it is preferred to use a material of protection which retains a certain elasticity and suppleness to satisfy the previously defined criterion. Certain epoxy resins and acrylates may be suitable.

In the example of FIG. 2, tests carried out with at least a hundred repetitive bends with a radius of curvature equal to 0.5 mm have were conclusive with a label without coating on the antenna. In the example of FIG. 3, other bending tests at a radius of 2 mm have not not affected the operation of the above tags.

Such manipulations are impossible and / or not recommended with prior art chip and interface devices.

The advantage of the label is that it can be incorporated into very fine and / or very flexible products and go unnoticed by the eye and touch so much its mechanical characteristics can be close or lower than the product. The product obtained can in particular have the touch a film or even a cigarette sheet. Such a device can find applications as a discrete insertable electronic device or superimposable in particular on fine products such as lining textile clothing, leather, sheet products, sheet films, products and cardboard packaging, but also and first act as a separate label whole. The device of the invention in the form of a label can also be part of the film constituting the product or the packaging, the antenna being by example made on a fabric, or a wrapping film itself.

Insofar as the support can be thin itself and undergo repetitive folds, the device is able to follow the resulting deformations without deterioration. It therefore performs a function identification with more reliability than the devices of the prior art in such conditions of use.

In FIG. 4, the interface is produced on a continuous strip 24 of film support 1. The microcircuit is advantageously arranged in a corner of the support film and directly on it. We preferably choose to position the chip in the corner of the label to reduce mechanical stress related to handling, but also to have an area available to the largest possible impression.

The strip 24 comprises a conductive frame (C) continuous around the interface and sights (p) intended for location and indexing / positioning of the interface during the various process operations described below. The conductive frame makes it possible to stiffen the strip of the support film and to reduce the costs and time of engraving if necessary. Lines fictitious reported in dotted lines on the strip illustrate cutting lines delimiting the device.

The antenna designs are designed based on the frequency of chosen operation and to optimize the range (case without contact)

In the example, the antenna 2 is drawn on the support film of so as to be able to communicate at a distance greater than 8 cm and preferably greater than 50 cm (passive case, i.e. without battery) and greater at 1 to 2 m (active case i.e. with battery). The size of the turns is chosen maximum and their number optimized to reach the expected distances, (in general, 4 to 6 turns are necessary at frequencies of 13 Mhz about).

The spacing between the turns depends on the method of making the antenna. In the example, the pitch of the turns is 1 mm, to compare with current devices where steps of 0.05 mm to 0.4 mm are rather reached.

To join the ends of the antenna to the microcircuit, the invention has preferably use a construction with "strap" as visible on the figure 5.

According to another variant not shown, the device comprises advantageously a capacitor, not in the form of armatures each side of the film, but integrated into the chip. This allows to get rid of variations in the value of the capacitor linked in particular to variations film thickness and bypass antenna adjustment steps often tedious. This is also preferable when the backing film is not a good dielectric.

According to a feature not shown intended to simplify the device, the support film has interface elements on a single side, the capacitor can be attached above the support film, or better still be in the chip as before.

To avoid having long connection wires in the if the antenna has more than one turn and a relatively large pitch, we can design the turns so that they have a narrower width than elsewhere locally, only at the level of the microcircuit and its connections ..

More preferably, to decrease the length of the wires of connection while keeping a minimum thickness of the device, we can place the microcircuit directly on the support film and between the turns which contoume. The combination of the characteristics of this variant above further reduces costs

The microcircuit can also be placed on the turns but at the detriment to the height of the device and good seating of the microcircuit.

In other cases, the microcircuit can be placed on a track interface in order to increase stability and better grip by adhesive glue.

In FIG. 6, it can be seen that the interface of the device D comprises at least connection pads 16 on the visible side in the drawing. The microcircuit is arranged on the other side, perforations through the film allowing to access the connection areas in a known manner. If applicable, the chip can be incorporated into the recess of a compensation film described infra.

It also includes as an example prints such as bar codes 17, arranged over the major part, the connections and the chip being in the edge of the support film.

Alternatively, the interface can include both contacts and a antenna (not shown). The antenna can for example be arranged on the other side not visible in the drawing, the capacitor in the chip.

In FIG. 7, we see a chip card 18 outside ISO standards in force. It includes the device (D) with the support film 2, placed on a support card body 19 which may be of equal or greater dimension than the film, for example equal to at least twice that of the support film 2. The face of the device not carrying the chip is preferably placed contact with the card body 19. The microcircuit is oriented upwards at the opposite of the card body 19.

The card can also include a second sheet 20 arranged above the support film and can be the same size as the card 19 or cover only the device.

According to one embodiment of the invention (FIG. 8), the card 19 constitutes a film of compensation. It includes a closed recess 21 into which the coated microcircuit 4, the support film at the interface (1, 2) extending outside the cavity on the surface of the card body. Extension of the device outside the cavity is not annoying to the touch and visually due to the low thickness of the interface support film. We thus obtain a card which is substantially flat, with in addition a microcircuit protected by the cavity.

In accordance with other characteristics, the device can further comprise an annex miniature resonant circuit comprising a backup antenna and / or integrated capacitor arranged in the microcircuit so as to compensate for a failure of the antenna or capacitor arranged on the interface support film. It will thus be possible retrieve information stored on the chip using a reader specific contactless proximity, which gives more reliability to device.

To this end, the microcircuit is able to be powered and to communicate to proximity via the emergency antenna in case of antenna circuit failure support film.

In FIG. 9, it can be seen that the device comprises a film of compensation 22 disposed on an interface support film. The film of compensation can be placed on all kinds of interface support film as known from the prior art but it finds more justifications and of interests (exposed above) with those which are apt to be folded or crumpled according to the bending test above.

The compensation film has a recess 23 in which is find the microcircuit 4, its connections 7, 8 and the coating material 13. The wall of the recess is in contact with the coating material in the since it forms a formwork at least partly for the material. His thickness is preferably such that the recess 23 just exceeds the microcircuit and its coating.

The compensation film can be of any flexible material preferably for the intended applications. In the example, we used a PE polymer material with a thickness of 200 µm, for a 150 µm chip and connections with wires. We have shown that it is possible to use a compensating film of less than 50 μm for a chip at 50 μm and a Flip chip type connection or by depositing conductive glue of the "silver-glue" type (patent applications FR-A-2 761 697 or FR-A-2 761 698). Allowing in this case to obtain a chip device of 110 µm max. Layer 22 is itself printable.

The device may further comprise at least one layer of protection / personalization 20 and / or adhesive layer 21 on at least one of the faces of the support film or of the compensation film.

The label thus produced can include all the functions and finishes of a normal label in addition to its identification functions electronic with the utmost discretion given its thinness and flexibility. If necessary, a self-adhesive adhesive film can be placed on the compensation film so as to direct the recess against an object to be label and thus conceal the presence of a chip.

As a variant, the compensation film is itself a mass adhesive of any known type, preferably thick and with or without film removable protector. In this case, it is the adhesive mass itself which at least partially compensates for the height of the microcircuit.

The label may include a double identification, in particular by a barcode printed on sheet 20 (Figures 9 and 6) and by a code corresponding digital stored in the memory of the integrated circuit.

The process for manufacturing the devices of the invention will now be described with reference to Figures 10, 11 and 11A.

According to a first step, an insulating support film 1 is provided, provided with less than a plane conductive interface 2, 9. It is called in the description of film support at interface.

It can be obtained by a multitude of known methods such as etching, screen printing of conductive ink, selective deposition of material conductor, cutting a rolled metal and rolling it on a support film, printed circuit technique, the embedding of conductive wires on a insulating support, etc.

In the example, and according to a characteristic of the invention, it is preferred use an engraving process for printed or lithographed patterns on less a conductive film previously fixed on the support film in particular by lamination or extrusion. We can thus obtain if necessary interfaces on each side of the support film.

The support film and the interface are chosen in accordance with indications given above relating to their mechanical properties and their thickness. The material of the metallic film is in the example aluminum preferred to copper due in particular to its price and ductility despite electrical performance lower than that of copper.

The choice of the engraving method supposes the use of an ink of masking of the tracks which generates an expensive withdrawal step after the engraving. We prefer to keep this ink on the interface to protect aluminum against oxidation and for an aesthetic aspect except locally at the level of the connection pads with the microcircuit to allow the welding. Local withdrawal can be carried out in particular by scraping mechanical or laser.

Alternatively, one can form the interface with a substance conductive with elastic polymer base and charged with metallic particles such as conductive ink. The elasticity of the polymer base is susceptible to meet the folding criteria. The deposit can be made for example by screen printing.

Then, at least one microcircuit is fixed on the support film to interface, and we connect it to the interface.

All operations are preferably carried out from strips of interface support film having a plurality of interfaces (antenna patterns for example) and being supplied in rolls or coils 24. The strips are routed to the various existing fixing stations 25 microcircuits 4, connection 26 and if appropriate coating 27.

As the backing film is particularly thin, fragile or stretchable, it is not possible to use drive means with pins which mesh on lateral perforations movies. We use suitable means of transport properties of the film. In particular, we use means of routing subject to a tension of the support film and which include means for measurement and / or adjustment of the tension of the support film to avoid damage by stretching. The training can for example be performed by drive rollers 28 or by grippers.

In the example, two interface patterns have been represented according to the width but we prefer to use widths greater than 80 mm with more reasons, in particular for a question of mechanical strength and productivity.

Fixing and connection of the microcircuit.

The fixing of the microcircuit can be carried out by any means in particular two-component, thermoadhesive, photoactivable adhesives, etc. In the example, we prefer to use an adhesive that can be activated on the shelves ultraviolet due in particular to its rapid setting, the low level of required temperature and reduced energy requirement.

For connection, there are different ways known more or less proven and emerging such as gold wire or wire welding aluminum, deposit of conductive adhesives, or of the "Flip chip" type with the inverted microcircuit, studs down, etc. In these last two cases, we can overcome the coating and the connection heights are low.

In accordance with a characteristic of the invention, the connection of the microcircuit by ultrasonic welding of selected conductive wires preferably aluminum.

This technique is contraindicated a priori on support films to very flexible and / or soft interface. In the field of the smart card, in fact, the ultrasonic welds of conductive wires are reserved for hard and rigid glass-based support sheets epoxy, polyimides and copper interface with type surface treatment Ni-Au.

In the state of the art of ultrasonic welding, recourse is had to a welding tool in the shape of a point from which emerges a welding wire. At during welding we just press the point on the metal studs interface or silicon chip resting on the support sheet.

The inventors have found that attempts at ultrasonic welding performed on interface supports based on soft materials such as PE or PP, or even PET (depending on its quality) to replace those commonly used used and with a thickness greater than about 75 µm for example 100 µm were doomed to fail, since the welding was not done or was of good quality poor non-industrial or non-reproducible.

The inventors have however succeeded in making quality welds industrial and reproducible on the condition of moving below a certain thickness threshold. In fact, below this threshold, they discovered that the higher the material is thin the better the weld. This is true even with aluminum wires which are very difficult to weld.

This separate threshold depending on the material is set at around 75 µm for the PE and PP.

An improvement in the reproducibility of the weld was obtained by plating at least the area of the support film (weld area) on which is going weld, flat on a fixed and hard reference plane.

The support film is plated by mechanical means or preferably by aspiration. In the latter case, we have a circuit in the fixed plane around the weld area.

So we were able to adapt a common connection technique particularly economical in order to make it reliable in the case of the invention

An interlayer film (not shown) is placed on the support film interface as soon as the microcircuit has been fixed to it so that it can be wound up correctly without damaging the microcircuits.

Linking of interface elements.

The connection interface elements possibly arranged each side of the support film can be connected through the film support by various known ways of the state of the art in particular by making metallized holes, filling a hole with a material conductor or electric shock etc.

However. thanks to the thinness of the support film of the invention and of the interfaces, and with their aforementioned characteristics, advantageously is carried out these connections by mechanical actions with perforations or tears local, stamping, or more advantageously by riveting, or ultrasound with very specific shape tools.

This procedure is particularly economical in the as it is carried out without adding material, in one step easily can be integrated and generally masked in the manufacturing process of the device or interface support film.

Coating step.

For the coating step, we can have the coating material located just on a microcircuit location area or extend to the whole support film surface. In the first case, a drop of the material for example a resin. In the second case, you can deposit the material by coating, screen printing etc. Preferably, it is deposited by spray.

The polymerization of glues and resins, conductive or not, varnish, can be done by a heat supply (thermal), localized or not and / or without overheating, in particular by radiation at certain wavelengths, for example UV, or by a mixture of two reagents.

We choose to carry out cold in particular at a lower temperature at 80 ° C and with rapid polymerization time, all stages of polymerization of adhesive adhesives and / or resins themselves intended for other purposes than coating. They are carried out for some under ultraviolet radiation. Preferably, these steps are carried out at ambient temperature.

Fixing film fixing step.

In accordance with another aspect of the invention, the process comprises a step according to which a film of compensation 22, also shown in FIG. 10, on the support film to interface (1, 2). This compensation film has at least one perforation 23 corresponding to a microcircuit location. In the illustrated example in FIG. 10, a strip 22 from a roller 29 comprising a plurality of perforations. Preferably used for this purpose non-polymerizable pressure-sensitive adhesives and / or glues.

This step is preferably carried out before fixing the microcircuit. It is also possible but more difficult to laminate or fix the film of compensation after the fixing or connection or coating operation microcircuit.

As already mentioned above, this step can be carried out in relationship with any supporting film interface, but it takes more interest and meaning with the interface support film capable of being folded as indicated above.

The recess is advantageously used to define a protective space of the microcircuit during the subsequent stages of winding, storage, but also to serve as a formwork for a coating material which is poured in operation 27.

Additional steps.

The method may also include an additional step consisting in securing an additional layer 30 of decoration or protective or adhesive on at least one of the two sides of the label. In the example, an adhesive layer 30 is fixed with its protective film after the transfer of the microcircuit.

Alternatively, one can provide a support film already comprising minus an additional layer, for example adhesive and protected by removable membrane.

Cutting and weeding stage, slitting.

Following the engraving operation, a continuous frame may remain (frame c in Figure 4) around the devices, which has the advantage of strengthening the support film during the process steps. This frame will then be removed by cutting. The device can be cut, for example by cookie cutter, to extract it in bulk from a strip 24 of support film to interface.

In another case, we prefer to keep the devices kept on tape or roll. For this purpose, it should first be fixed under the strip 24 of FIG. 4, a two-sided adhesive strip with a film of removable protection. The cutting is done so as not to cut the film of protection. A weeding stage then follows the cutting stage and there remains the adhesive devices on the protective film.

The strip is also cut longitudinally to the width desired (split).

Rollers are thus provided with adhesive labels on the desired format evenly spaced on the protective roller of the adhesive. The label can be affixed to any product. In other cases, use temporary adhesives or non-adhesive recollages, which allows to do the whole process in roll and deliver in roll the devices, cards, tickets, non-adhesive labels etc.

Realization of large area products containing the device.

In FIG. 11, smart cards conforming to the invention. The steps, and the references are identical to those of the figure 10 except that the roller 24 has a single row of interface pattern 2. The compensation film is a larger sheet than film support and has a single row of perforations. The film 30 is still a protective and / or decorative film or optional adhesive.

It should be noted that this process allows processing of cards in reel as for tickets and labels obtained previously. Roll processing can also be extended until packaging and delivery to the end user.

The compensation film can be of any kind, in particular paper, leather, non-woven or woven fibers, polymers etc. In the example, the compensation film is a PE with a thickness equal to 200 μm and which has an area equal to twice that of the device.

After cutting, we obtain a smart card of figure 11 A. The case if necessary, a film 20 equivalent to film 30 can be placed on the card. so as to mask the perforation 23.

To obtain the card conforming to FIG. 8, one proceeds from identical to the process illustrated in Figure 11, except that the compensation film is laminated after the fixing and connection steps with coating if necessary. In this case, the recesses 23 are not through and thus form cavities 21, the compensation film becoming the card body 19 after cutting it.

Note that the remarks made in Figure 10 remain valid for figure 11.

Conversely not shown, a compensation film can be used 29 narrower than the interface support film, in particular at the edge of this last.

We give below complements relating to certain problems overcome by the inventors.

The far-reaching objective is a problem because it is incompatible with the the cost reduction objective.

The far-reaching goal involves having a good driver electric as interface, (a wire of round section, is better conductor a cut or engraved sheet of rectangular section; copper is better conductor than Aluminum and significantly better than ink or conductive paste ....).

It also involves increasing the number of turns and the surface antenna, which would mean increasing the area of the circuit and its footprint.

It also involves having dimensions and a definition of optimized tracks, (the narrower the tracks, the more the antenna towers closer together, the larger the size of the towers, and therefore the large flow.

The solution to the cost problem which is to degrade the properties support interface films goes against the above.

In addition, this solution which results in retaining an interface support film (especially PE or PP and aluminum) very flexible, generates including the following problems.

Current processes are not suitable a priori, such films support that has never been used in the manufacture of semiconductor modules.

The flexibility of the support film is a priori incompatible with the hardness of a silicon chip and with the fragility of the chip and its connections.

The flexibility and thinness of the support films pose drawbacks for collective treatment in the form of rolls. For example, the collective treatment implies a very good positioning necessary for the stage of deferral and protection of the chip, and more particularly for the solder wire. Such support film cannot be provided with perforations drive, there is no mechanical guidance possible as for 35 mm films.

The use of degraded conductive materials (for example, aluminum or copper without a specific surface layer, in particular Ni-Au type) poses problems of weldability increased by problems oxidation.

The PP or PE / aluminum complexes envisaged by the inventors to form the basis for interface support films have inks that are left on the surface of the metal and cannot be welded. Their removal is costly and results in the formation of a layer insulating oxide.

The use of a support film with a degraded interface, in particular in rigidity (absence of Ni) leads to the retention of soft materials, which generates welding problems described above. In addition, very flexible materials generally melt at temperatures used in art processes prior.

The solution ideally involves adapting the processes current ones using 35 mm spools, to wide spools greater than 80 mm.

Claims (39)

1. An electronic chip device comprising a support film with interface having a support film. (1) and at least one flat conductive interface (2, 16) disposed directly on said support film (1), and a microcircuit (4) connected to said interface, the device comprising in addition a height compensation film (22) disposed on the support film (1) and on at least part of the interface, said compensation film (22) having a recess (21, 23) containing said microcircuit (4), its connections (7, 8) and a material for encapsulating (13) the microcircuit (4).
2. A device according to Claim 1, characterised in that the support film (1) and the interface are capable of being creased or folded together without damage at a radius of curvature less than 2.5 mm, and preferably less than 1 mm.
3. A device according to Claim 1 or 2, characterised in that the encapsulation material (13) is encased at least partially by said recess (21, 23).
4. A device according to one of the preceding claims, characterised in that the support film (1) has a thickness less than 75 µm and preferably between 10 µm and 30 µm.
5. A device according to one of the preceding claims, characterised in that the support film (1) has an elongation at break greater than 80%, and/or Shore hardness less than 80, and/or a glass transition temperature Tg below 0°C, and/or a melting temperature below 130°C.
6. A device according to one of Claims 1 to 5, characterised in that the support film (1) can notably be chosen from amongst PP, PE and PET.
7. A device according to one of the preceding claims, characterised in that the interface is made of aluminium.
8. A device according to one of the preceding claims, characterised in that the flat conductive interface is constituted by turns (2) of a flat antenna (3) disposed in a spiral on the support film (1), and in that the microcircuit (4) is disposed outside the turns (2).
9. A device according to one of the preceding claims, characterised in that the support film (1) has a so-called strap interface element (11) on the other face in order to bring back at least one end (6) of the antenna (3) to the vicinity of the chip (4).
10. A device according to one of the preceding claims, characterised in that the width of the turns (2) in the region of the microcircuit (4) is thinner than elsewhere so as to connect the microcircuit (4) directly onto the ends (6) with a small length of connecting wire.
11. A device according to one of the preceding claims, characterised in that the microcircuit (4) is disposed between the turns (2) directly on the support film (1).
12. A device according to one of the preceding claims, characterised in that the microcircuit (4) is disposed in a corner of the support film (1) and directly on top.
13. A device according to one of the preceding claims, characterised in that the interface has at least one antenna turn (2) formed so as to be able to communicate at a distance greater than 8 cm and preferably greater than 50 cm.
14. A device according to one of the preceding claims, characterised in that the interface has connection areas (16).
15. A device according to one of the preceding claims, characterised in that it has an encapsulation material (13) over at least the microcircuit (4), its connections and at least one portion of the interface.
16. A device according to one of the preceding claims, characterised in that it has at least one protection/customization layer (20) and/or adhesive layer (30) on at least one of its faces.
17. A device according to one of the preceding claims, characterised in that it has a resonance capacitor (16a, 17b) constituted by two conductive surfaces disposed either side of the support film (10).
18. A device according to Claim 17, characterised in that the capacitor (16a, 17b) has an adjustment.
19. A device according to one of the preceding claims, characterised in that it has an integrated capacitor and/or a backup antenna included in the microcircuit.
20. A device according to Claim 19, characterised in that the microcircuit (4) is capable of being powered and of communicating close-in via the backup antenna in the case of failure of the antenna circuit of the support film (1).
21. A smart card (18), characterised in that it has a card body (19, 22) on which there is fixed the device (D) according to one of the preceding claims, the card body having a surface area greater than or equal to that of the device and preferably at least double.
22. A smart card (18), characterised in that it has two outer leaves (18, 19, 20, 30) between which there is disposed the device according to one of Claims 1 to 20.
23. A smart card (18) comprising a card body (19) having a cavity (21), characterised in that it includes the device according to one of Claims 1 to 20, the microcircuit (4) being disposed in the cavity (21), the support film (1) and the interface extending outside the cavity (21) over the surface of the card body (19).
24. A method for producing an electronic chip device comprising a support film with interface having a support film (1) and at least one flat interface deposited directly on the support film (1) and at least one microcircuit (4) connected to said interface, said method having steps according to which at least said support film (1) with interface is supplied, at least said microcircuit (4) is fixed onto the support film (1) with interface, and it is connected to the interface, the method having a step according to which a height compensation film (22) is fixed onto said support film (1) and onto at least part of the interface, said compensation film (22) having at least one recess (21, 23) corresponding to a location for a microcircuit (4), and a step of encapsulating the microcircuit (4) with a encapsulation material (13).
25. A method according to Claim 24, characterised in that the compensation film (22) is deposited before the fixing of the microcircuit (4).
26. A method according to either of Claims 24 or 25, characterised in that the encapsulation material (13) is poured only into the recess (21, 23) in the compensation film (22).
27. A method according to either of Claims 24 or 26, characterised in that the compensation film (22) is deposited after the fixing of the microcircuit (4) or the encapsulation thereof.
28. A method according to one of Claims 24 to 27, characterised in that the support film (1) with interface is supplied as a strip on a roll (24), and in that conveying means slaved to the tension of the support film (1) are used for conveying it to at least one workstation (25, 26, 27).
29. A method according to one of Claims 24 to 28, characterised in that the connection of the microcircuit (4) is implemented by ultrasonic welding of conductive wires (7, 8).
30. A method according to Claim 29, characterised in that conductive wires (7, 8) made of aluminium are used.
31. A method according to either of Claims 29 or 30, characterised in that, for welding, at least the location (zp) of the microcircuit (4) on the support film (1) is plated on a fixed reference plane.
32. A method according to Claim 31, characterised in that the support film (1) is vacuum plated.
33. A method according to one of Claims 24 to 32, characterised in that the interface is produced on the support film (1) according to an aluminium etching technique.
34. A method according to one of Claims 24 to 33, characterised in that the interface elements and contact pads (5, 6) are connected through the support film (1) by means of perforations/mechanical openings.
35. A method according to one of Claims 24 to 34, characterised in that it also has a step according to which an encapsulation material (13) is deposited on at least the microcircuit (4) and its connections (7, 8).
36. A method according to one of Claims 24 to 35, characterised in that the encapsulation material (13) is poured into the recess (23) formed by a perforation of the compensation film (22).
37. A method according to one of Claims 24 to 36, characterised in that it has at least one additional step consisting in immovably attaching an adhesive layer (30) with a removable protective film onto at least one face of the label.
38. A method according to one of Claims 28 to 37, characterised in that the strip has a plurality of interfaces, and in that it has a step consisting in cutting off each device.
39. A method according to Claims 37 and 38, characterised in that said adhesive layer (30) provided with the protective film is supplied as a continuous strip, in that the devices are cut off while remaining fixed on the protective film, and in that undesirable elements between the devices are removed.

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